Field of the Invention
The present invention relates to an image pickup apparatus which corrects deterioration of a shot image to achieve high definition.
Description of the Related Art
For an object shot via an image pickup optical system, light emitted from one point cannot be converged to another point and has a minute spread due to an influence of a diffraction, an aberration, or the like that occurs in the image pickup optical system. Such a minutely-spread distribution is referred to as a PSF (point spread function). Due to the influence of the image pickup optical system, the shot image is formed with the PSF convoluted with the image, and accordingly, the image is blurred and its resolution is deteriorated.
Recently, the shot image is typically stored as electronic data, and image restoration has been proposed which corrects an image deterioration caused by an optical system by performing image processing. However, when the shot image is deteriorated by a hand shake or an amount of the aberration of the image pickup optical system is large, it is difficult to perform the image restoration effectively. Furthermore, when an image is shot with a high ISO sensitivity in which a noise easily occurs, the noise is significantly amplified by the image restoration and thus it is difficult to acquire a high-definition image.
Japanese Patent Laid-open No. 2007-19973 discloses a configuration in which a shutter speed increases while performing a hand shake correction (image stabilizing operation) in order to suppress the deterioration of an image quality caused by the hand shake.
However, it is difficult to acquire a high-quality shot image considering image correction intentionally since a user does not know a condition (shooting condition to achieve an effect of image restoration) to perform the image restoration more effectively even when a function of the image restoration is incorporated in an image pickup apparatus.
In this regard, Japanese Patent Laid-open No. 2007-19973 does not consider a shooting condition such as a focal length of the image pickup apparatus, an F number, and an object distance, and a shutter speed. In other words, Japanese Patent Laid-open No. 2007-19973 does not disclose a configuration to perform the image restoration more effectively.